[Sanitizers] Make abort_on_error common flag.

[samsonov]

Summary

Teach all sanitizers to call abort() instead of _exit() after printing
an error report, if requested. This behavior is the default on Mac OS.

[kcc]

LGTM

[samsonov]

Thank you!

Kuba, could you take a look if this change works on Mac as expected?

[kubamracek]

Alexey, there are two test failures with this change. The test sanitizer_common/TestCases/Darwin/abort_on_error.cc fails with

Undefined symbols for architecture i386:
  "__sanitizer::Die()", referenced from:
      _main in abort_on_error-4d1da3.o
ld: symbol(s) not found for architecture i386

because __sanitizer::Die() is not an exported symbol. The second failure is in sanitizer_common/TestCases/options-include.cc:

Exit Code: 1
Error: Abort trap: 6

This is because the test overrides %tool_options without inheriting the default ones (like we do with %env_asan_opts in ASan lit tests). Therefore the test crashes on OS X instead of just quitting with a non-zero exit code.

[samsonov]

Speculatively fix test failures on Mac OS.

[samsonov]

Kuba, could you please check if the updated version works for you?

[kubamracek]

%env_tool_opts='' not --crash %run %t doesn't work because it expands to env ASAN_OPTIONS=abort_on_error=0:'' not --crash .... How about introducing something like:

config.substitutions.append( ('%env_tool_opts_var_name', tool_options))

and then using it with %env_tool_opts_var_name='' not --crash %run %t? With that, all the tests pass (on OS X).

Kuba

[samsonov]

Thank you! I'll follow this suggestion and submit the CL shortly.

lib/asan/asan_flags.inc

ASAN_FLAG(
     "Number of seconds to sleep between printing an error report and "
     "terminating the program. Useful for debugging purposes (e.g. when one "
     "needs to attach gdb).")
 ASAN_FLAG(bool, check_malloc_usable_size, true,
           "Allows the users to work around the bug in Nvidia drivers prior to "
           "295.*.")
 ASAN_FLAG(bool, unmap_shadow_on_exit, false,
           "If set, explicitly unmaps the (huge) shadow at exit.")
-ASAN_FLAG(
-    bool, abort_on_error, SANITIZER_MAC,
-    "If set, the tool calls abort() instead of _exit() after printing the "
-    "error report.")
 ASAN_FLAG(bool, print_stats, false,
           "Print various statistics after printing an error message or if "
           "atexit=1.")
 ASAN_FLAG(bool, print_legend, true, "Print the legend for the shadow bytes.")
 ASAN_FLAG(bool, atexit, false,
           "If set, prints ASan exit stats even after program terminates "
           "successfully.")
 ASAN_FLAG(

lib/asan/asan_rtl.cc

static void AsanDie() {
   if (flags()->unmap_shadow_on_exit) {
     if (kMidMemBeg) {
       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
     } else {
       UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
     }
   }
-  if (flags()->abort_on_error)
-    Abort();
 }
 
 static void AsanCheckFailed(const char *file, int line, const char *cond,
                             u64 v1, u64 v2) {
   Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
          line, cond, (uptr)v1, (uptr)v2);
   // FIXME: check for infinite recursion without a thread-local counter here.
   PRINT_CURRENT_STACK_CHECK();

lib/sanitizer_common/sanitizer_common.cc

 
 void NORETURN Die() {
   if (UserDieCallback)
     UserDieCallback();
   for (int i = kMaxNumOfInternalDieCallbacks - 1; i >= 0; i--) {
     if (InternalDieCallbacks[i])
       InternalDieCallbacks[i]();
   }
+  if (common_flags()->abort_on_error)
+    Abort();
   internal__exit(common_flags()->exitcode);
 }
 
 static CheckFailedCallbackType CheckFailedCallback;
 void SetCheckFailedCallback(CheckFailedCallbackType callback) {
   CheckFailedCallback = callback;
 }
 

lib/sanitizer_common/sanitizer_common_nolibc.cc

 //===-- sanitizer_common_nolibc.cc ----------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains stubs for libc function to facilitate optional use of
 // libc in no-libcdep sources.
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_platform.h"
 #include "sanitizer_common.h"
+#include "sanitizer_libc.h"
 
 namespace __sanitizer {
 
 #if SANITIZER_LINUX
 void WriteToSyslog(const char *buffer) {}
 #endif
 
-}
+void Abort() { internal__exit(1); }
+
+}  // namespace __sanitizer

lib/sanitizer_common/sanitizer_flags.inc

 COMMON_FLAG(bool, strict_memcmp, true,
           "If true, assume that memcmp(p1, p2, n) always reads n bytes before "
           "comparing p1 and p2.")
 COMMON_FLAG(bool, decorate_proc_maps, false, "If set, decorate sanitizer "
                                              "mappings in /proc/self/maps with "
                                              "user-readable names")
 COMMON_FLAG(int, exitcode, 1, "Override the program exit status if the tool "
                               "found an error")
+COMMON_FLAG(
+    bool, abort_on_error, SANITIZER_MAC,
+    "If set, the tool calls abort() instead of _exit() after printing the "
+    "error report.")

test/sanitizer_common/TestCases/Darwin/abort_on_error.cc

+// Check that sanitizers on OS X crash the process by default (i.e.
+// abort_on_error=1). See also Linux/abort_on_error.cc.
+
+// RUN: %clangxx %s -o %t
+
+// Intentionally don't inherit the default options.
+// RUN: %env_tool_opts='' not --crash %run %t 2>&1
+
+// When we use lit's default options, we shouldn't crash.
+// RUN: not %run %t 2>&1
+
+int global;
+
+int main() {
+  volatile int *a = new int[100];
+  delete[] a;
+  global = a[0];  // use-after-free: triggers ASan report.
+  return 0;
+}

test/sanitizer_common/TestCases/Darwin/lit.local.cfg

+def getRoot(config):
+  if not config.parent:
+    return config
+  return getRoot(config.parent)
+
+root = getRoot(config)
+
+if root.host_os not in ['Darwin']:
+  config.unsupported = True

test/sanitizer_common/TestCases/Linux/abort_on_error.cc

+// Check that sanitizers call _exit() on Linux by default (i.e.
+// abort_on_error=0). See also Darwin/abort_on_error.cc.
+
+// RUN: %clangxx %s -o %t
+
+// Intentionally don't inherit the default options.
+// RUN: %env_tool_opts='' not %run %t 2>&1
+
+// When we use lit's default options, we shouldn't crash either. On Linux
+// lit doesn't set options anyway.
+// RUN: not %run %t 2>&1
+
+namespace __sanitizer {
+void Die();
+}
+
+int main() {
+  __sanitizer::Die();
+  return 0;
+}

test/sanitizer_common/lit.common.cfg

 # -*- Python -*-
 
 # Setup source root.
 config.test_source_root = os.path.join(os.path.dirname(__file__), "TestCases")
 
 config.name = "SanitizerCommon-" + config.tool_name
 
+default_tool_options = []
 if config.tool_name == "asan":
   tool_cflags = ["-fsanitize=address"]
   tool_options = "ASAN_OPTIONS"
 elif config.tool_name == "tsan":
   tool_cflags = ["-fsanitize=thread"]
   tool_options = "TSAN_OPTIONS"
 elif config.tool_name == "msan":
   tool_cflags = ["-fsanitize=memory"]
   tool_options = "MSAN_OPTIONS"
 elif config.tool_name == "lsan":
   tool_cflags = ["-fsanitize=leak"]
   tool_options = "LSAN_OPTIONS"
 else:
   lit_config.fatal("Unknown tool for sanitizer_common tests: %r" % config.tool_name)
 
 config.available_features.add(config.tool_name)
 
+if config.host_os == 'Darwin':
+  # On Darwin, we default to `abort_on_error=1`, which would make tests run
+  # much slower. Let's override this and run lit tests with 'abort_on_error=0'.
+  default_tool_options += ['abort_on_error=0']
+default_tool_options_str = ':'.join(default_tool_options)
+if default_tool_options_str:
+  config.environment[tool_options] = default_tool_options_str
+  default_tool_options_str += ':'
+
 clang_cflags = config.debug_info_flags + tool_cflags + [config.target_cflags]
 clang_cxxflags = config.cxx_mode_flags + clang_cflags
 
 def build_invocation(compile_flags):
   return " " + " ".join([config.clang] + compile_flags) + " "
 
 config.substitutions.append( ("%clang ", build_invocation(clang_cflags)) )
 config.substitutions.append( ("%clangxx ", build_invocation(clang_cxxflags)) )
 config.substitutions.append( ("%tool_name", config.tool_name) )
-default_tool_options_str = ''
 config.substitutions.append( ('%env_tool_opts=',
                               'env ' + tool_options + '=' + default_tool_options_str))
 
 config.suffixes = ['.c', '.cc', '.cpp']
 
 if config.host_os not in ['Linux', 'Darwin']:
   config.unsupported = True

test/ubsan/lit.common.cfg

 # -*- Python -*-
 
 import os
 
 def get_required_attr(config, attr_name):
   attr_value = getattr(config, attr_name, None)
   if attr_value == None:
     lit_config.fatal(
       "No attribute %r in test configuration! You may need to run "
       "tests from your build directory or add this attribute "
       "to lit.site.cfg " % attr_name)
   return attr_value
 
 # Setup source root.
 config.test_source_root = os.path.dirname(__file__)
 
+default_ubsan_opts = []
 # Choose between standalone and UBSan+ASan modes.
 ubsan_lit_test_mode = get_required_attr(config, 'ubsan_lit_test_mode')
 if ubsan_lit_test_mode == "Standalone":
   config.name = 'UBSan-Standalone-' + config.target_arch
   config.available_features.add("ubsan-standalone")
   clang_ubsan_cflags = []
 elif ubsan_lit_test_mode == "AddressSanitizer":
   config.name = 'UBSan-ASan-' + config.target_arch
   config.available_features.add("ubsan-asan")
   clang_ubsan_cflags = ["-fsanitize=address"]
-  config.environment['ASAN_OPTIONS'] = 'detect_leaks=0'
-  
-  # Platform-specific default ASAN_OPTIONS for lit tests.
-  if config.host_os == 'Darwin':
-    # On Darwin, we default to `abort_on_error=1`, which would make tests run
-    # much slower. Let's override this and run lit tests with 'abort_on_error=0'.
-    config.environment['ASAN_OPTIONS'] = 'abort_on_error=0'
+  default_ubsan_opts += ['detect_leaks=0']
 elif ubsan_lit_test_mode == "MemorySanitizer":
   config.name = 'UBSan-MSan-' + config.target_arch
   config.available_features.add("ubsan-msan")
   clang_ubsan_cflags = ["-fsanitize=memory"]
 elif ubsan_lit_test_mode == "ThreadSanitizer":
   config.name = 'UBSan-TSan-' + config.target_arch
   config.available_features.add("ubsan-tsan")
   clang_ubsan_cflags = ["-fsanitize=thread"]
 else:
   lit_config.fatal("Unknown UBSan test mode: %r" % ubsan_lit_test_mode)
 
+# Platform-specific default for lit tests.
+if config.host_os == 'Darwin':
+  # On Darwin, we default to `abort_on_error=1`, which would make tests run
+  # much slower. Let's override this and run lit tests with 'abort_on_error=0'.
+  default_ubsan_opts += ['abort_on_error=0']
+default_ubsan_opts_str = ':'.join(default_ubsan_opts)
+if default_ubsan_opts_str:
+  config.environment['UBSAN_OPTIONS'] = default_ubsan_opts_str
+  default_ubsan_opts_str += ':'
 # Substitution to setup UBSAN_OPTIONS in portable way.
 config.substitutions.append(('%env_ubsan_opts=',
-                             'env UBSAN_OPTIONS='))
+                             'env UBSAN_OPTIONS=' + default_ubsan_opts_str))
 
 def build_invocation(compile_flags):
   return " " + " ".join([config.clang] + compile_flags) + " "
 
 target_cflags = [get_required_attr(config, "target_cflags")]
 clang_ubsan_cflags += target_cflags
 clang_ubsan_cxxflags = config.cxx_mode_flags + clang_ubsan_cflags